neighbour: Use rcu_dereference() in pneigh_get_{first,next}().

Now pneigh_entry is guaranteed to be alive during the
RCU critical section even without holding tbl->lock.

Let's use rcu_dereference() in pneigh_get_{first,next}().

Note that neigh_seq_start() still holds tbl->lock for the
normal neighbour entry.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250716221221.442239-12-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 3ef797212618eed9a67a40b7ef9d7126606e1455..b76ff416b9a7aaa8bc0c0e70b057eae282bf4ec9 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -3309,10 +3309,10 @@ static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
 
        state->flags |= NEIGH_SEQ_IS_PNEIGH;
        for (bucket = 0; bucket <= PNEIGH_HASHMASK; bucket++) {
-               pn = rcu_dereference_protected(tbl->phash_buckets[bucket], 1);
+               pn = rcu_dereference(tbl->phash_buckets[bucket]);
 
                while (pn && !net_eq(pneigh_net(pn), net))
-                       pn = rcu_dereference_protected(pn->next, 1);
+                       pn = rcu_dereference(pn->next);
                if (pn)
                        break;
        }
@@ -3330,17 +3330,17 @@ static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
        struct neigh_table *tbl = state->tbl;
 
        do {
-               pn = rcu_dereference_protected(pn->next, 1);
+               pn = rcu_dereference(pn->next);
        } while (pn && !net_eq(pneigh_net(pn), net));
 
        while (!pn) {
                if (++state->bucket > PNEIGH_HASHMASK)
                        break;
 
-               pn = rcu_dereference_protected(tbl->phash_buckets[state->bucket], 1);
+               pn = rcu_dereference(tbl->phash_buckets[state->bucket]);
 
                while (pn && !net_eq(pneigh_net(pn), net))
-                       pn = rcu_dereference_protected(pn->next, 1);
+                       pn = rcu_dereference(pn->next);
                if (pn)
                        break;
        }